What does that do to your life and identity? How does your relationship hold up to all of that? How do you not become bitter enemies??

Well, it turns out that they're both the best of friends… and the biggest rivals!

Here's what Venus had to say:

"It's a once in a lifetime experience, a once in a generation experience. I can't describe how wonderful it is, it's something I've always had as well. I also realize it's something very special and I always have someone who knows what I'm going through!"

So who is the most competitive of the two? She continues:

"We're very competitive, both of us! You can see it more with her and how she's feeling on the court, and me I'm just a little more… calm! We handle it different ways! We're two different people! To get to this level you HAVE to be extremely competitive!"

She even goes on to say that Serena is the toughest player she's ever faced, but she's also the player she has the most respect for! They're rivals on the court, but when they step off the court — they're friends and sisters!